Component parts which include titanium and carbon fiber-reinforced plastic may be assembled with standard aircraft fasteners. The fastener openings drilled in these parts may be subject to entry/exit burr which may reduce the fatigue strength of the titanium part. A key problem in the conventional drilling process is the difficulty and expense of disassembling, deburring and applying a chamfer to drilled parts in a time-effective and cost-effective manner. Therefore, an internal chamfering device and method which is suitable for deburring and chamfering drilled fastener openings in mating parts is needed.